煤粉燃烧火焰辐射光谱实验研究

针对煤粉燃烧辐射光谱问题，利用光纤光谱仪对煤粉平面火焰炉实验装置煤粉燃烧火焰辐射光谱进行了测量，详细分析了煤粉辐射光谱特征，并基于普朗克辐射传热定律，通过对光谱仪波长响应特性的标定，得到火焰绝对辐射强度随波长的分布情况，进而利用最小二乘法获得火焰温度与辐射率参数，由此提出基于煤粉燃烧火焰辐射光谱测量的火焰参数测量方法。利用该方法对不同燃烧条件下煤粉燃烧参数进行测量，开展了不同燃烧参数下煤粉火焰辐射光谱实验研究，研究结果表明：煤粉燃烧火焰辐射在200～1 100 nm波段具有较强且连续的光谱特征，基于普朗克辐射定律与最小二乘法可实现煤粉燃烧火焰温度与辐射率的测量;煤粉燃烧火焰辐射光谱在590，766，769和779 nm附近可见明显的Na和K等碱金属痕量元素原子光谱发射谱线，并且这些原子谱线的出现与火焰温度有关;随着煤粉浓度的提高，虽然燃烧温度变化不大，但由于火焰辐射率的增加，造成辐射光谱强度的大幅提升。这对锅炉煤粉燃烧优化具有重要参考价值。

Research on Radiation Spectrum of Pulverized Coal Combustion Flame

In order to study on radiation spectrum of pulverized coal flame,radiation spectrums of pulverized coal flame on flat flame burner were measured with fiber optic spectrometer and the radiation characteristic was analyzed in detail.Distribution curves of radiation intensity of flame with wavelength were obtained based on Planck’s Law and calibration by using blackbody furnace.Then,combustion parameters such as temperature and emissivity were calculated by using least square method.There-fore,the measurement method based on radiation spectrum of pulverized coal flame was proposed.And the experimental investi-gations on pulverized coal flame under different conditions were carried out with this method.The result shows that the radiation spectrum of pulverized coal flame is significant and continuous in the wavelength ranging from 200 to 1 100 nm.The temperature and emissivity of flame can be determined by using Planck’s Law and least square method.Meanwhile,emission peaks of alkali metal such as sodium and potassium appear on the radiation spectrum of pulverized coal combustion flame near 590,766,769 and 779 nm,and the appearance of these emission lines is related with temperature.When the concentration of pulverized coal is in-creasing,the temperature of pulverized coal flame has a little change but the emissivity changes obviously.The intensity of radia-tion is increasing greatly with emissivity.It can provide important reference for combustion optimization of boiler.